Characterization of Na+currents regulating intrinsic excitability of optic tectal neurons DOI Creative Commons
Adrian C. Thompson, Carlos D. Aizenman

Life Science Alliance, Год журнала: 2023, Номер 7(1), С. e202302232 - e202302232

Опубликована: Ноя. 2, 2023

Developing neurons adapt their intrinsic excitability to maintain stable output despite changing synaptic input. The mechanisms behind this process remain unclear. In study, we examined Xenopus optic tectal and found that the expressions of Na v 1.1 1.6 voltage-gated + channels are regulated during changes in excitability, both development becsuse visual experience. Using whole-cell electrophysiology, demonstrate existence distinct, fast, persistent, resurgent currents tectum, show these co-regulated with channel expression. antisense RNA suppress expression specific subunits, up-regulation expression, but not 1.1, was necessary for experience-dependent increases excitability. Furthermore, regulation also normal sensory guided behaviors. These data suggest through modulation a lesser extent plays crucial role controlling guiding circuitry.

Язык: Английский

The actin-spectrin submembrane scaffold restricts endocytosis along proximal axons DOI
Florian Wernert, Satish Babu Moparthi, Florence Pelletier

и другие.

Science, Год журнала: 2024, Номер 385(6711)

Опубликована: Авг. 22, 2024

Clathrin-mediated endocytosis has characteristic features in neuronal dendrites and presynapses, but how membrane proteins are internalized along the axon shaft remains unclear. We focused on clathrin-coated structures initial segment (AIS) their relationship to periodic actin-spectrin scaffold that lines axonal plasma membrane. A combination of super-resolution microscopy platinum-replica electron cultured neurons revealed AIS pits form within “clearings”, circular areas devoid mesh. Actin-spectrin disorganization increased pit formation. Cargo uptake live-cell imaging showed particularly stable. Neuronal plasticity-inducing stimulation triggered internalization through polymerization branched actin around them. Thus, spectrin regulate formation scission control at AIS.

Язык: Английский

Процитировано

9
Direct fluorescent labeling of NF186 and NaV1.6 in living primary neurons using bioorthogonal click chemistry DOI Creative Commons
Nevena Stajković, Yuanyuan Liu, Aleksandra Arsić

и другие.

Journal of Cell Science, Год журнала: 2023, Номер 136(12)

Опубликована: Июнь 8, 2023

The axon initial segment (AIS) is a highly specialized neuronal compartment that regulates the generation of action potentials and maintenance polarity. Live imaging AIS challenging due to limited number suitable labeling methods. To overcome this limitation, we established novel approach for live using unnatural amino acids (UAAs) click chemistry. small size UAAs possibility introducing them virtually anywhere into target proteins make method particularly complex spatially restricted proteins. Using approach, labeled two large components, 186 kDa isoform neurofascin (NF186; encoded by Nfasc) 260 voltage-gated Na+ channel (NaV1.6, Scn8a) in primary neurons performed conventional super-resolution microscopy. We also studied localization epilepsy-causing NaV1.6 variants with loss-of-function effect. Finally, improve efficiency UAA incorporation, developed adeno-associated viral (AAV) vectors neurons, an achievement could be transferred more systems such as organotypic slice cultures, organoids, animal models.

Язык: Английский

Процитировано

11
Axo-axonic synaptic input drives homeostatic plasticity by tuning the axon initial segment structurally and functionally DOI Creative Commons
Rui Zhao,

Baihui Ren,

Yujie Xiao

и другие.

Science Advances, Год журнала: 2024, Номер 10(31)

Опубликована: Авг. 2, 2024

Homeostatic plasticity maintains the stability of functional brain networks. The axon initial segment (AIS), where action potentials start, undergoes dynamic adjustment to exert powerful control over neuronal firing properties in response network activity changes. However, it is poorly understood whether this involves direct synaptic input AIS. Here, we show that changes GABAergic from chandelier cells (ChCs) drive homeostatic tuning AIS principal neurons (PNs) prelimbic (PL) region, while those parvalbumin-positive basket do not. This evident morphology, voltage-gated sodium channel expression, and PN excitability. Moreover, impact can be reflected animal behavior. Social behavior, inversely linked PL activity, shows time-dependent alterations tightly coupled Thus, AIS-originated PNs may counteract deficits elicited by imbalanced ChC presynaptic at cellular behavioral levels.

Язык: Английский

Процитировано

4
Live imaging of excitable axonal microdomains in ankyrin-G-GFP mice DOI Creative Commons
Christian Thome, Jan Maximilian Janssen, Seda Karabulut

и другие.

eLife, Год журнала: 2025, Номер 12

Опубликована: Фев. 3, 2025

The axon initial segment (AIS) constitutes not only the site of action potential initiation, but also a hub for activity-dependent modulation output generation. Recent studies shedding light on AIS function used predominantly post-hoc approaches since no robust murine in vivo live reporters exist. Here, we introduce reporter line which is intrinsically labeled by an ankyrin-G-GFP fusion protein activated Cre recombinase, tagging native Ank3 gene. Using confocal, superresolution, and two-photon microscopy as well whole-cell patch-clamp recordings vitro, ex , vivo, confirm that subcellular scaffold electrophysiological parameters cells remain unchanged. We further uncover rapid remodeling following increased network activity this model system, highly reproducible labeling over weeks. This novel allows longitudinal plasticity real-time thus provides unique approach to study broad range applications.

Язык: Английский

Процитировано

0
The dynamic axon initial segment: From neuronal polarity to network homeostasis DOI Creative Commons
Amélie Fréal, Casper C. Hoogenraad

Neuron, Год журнала: 2025, Номер 113(5), С. 649 - 669

Опубликована: Фев. 12, 2025

The axon initial segment (AIS) is a highly specialized compartment in neurons that resides between axonal and somatodendritic domains. localization of the AIS proximal part essential for its two major functions: generating modulating action potentials maintaining neuron polarity. Recent findings revealed incredibly stable generated from dynamic components can undergo extensive structural functional changes response to alterations activity levels. These activity-dependent structure function have profound consequences neuronal functioning, plasticity has emerged as key regulator network homeostasis. This review highlights functions AIS, architecture, how organization remodeling are influenced by developmental both acute chronic adaptations. It also discusses mechanisms underlying these processes explores dysregulated may contribute brain disorders.

Язык: Английский

Процитировано

0
FMRP Controls Neuronal Architecture and Synaptic Content of NMDA Receptors in Cultured Hippocampal Neurons DOI Creative Commons
Elisa Corti, Carlos B. Duarte

Journal of Molecular Neuroscience, Год журнала: 2025, Номер 75(2)

Опубликована: Апрель 2, 2025

Fragile X syndrome is the most common inherited form of intellectual disability and caused by transcriptional silencing Fmr1 gene lack fragile messenger ribonucleoprotein (FMRP). FMRP an RNA-binding protein that regulates synthesis synaptic proteins which are essential for proper brain function. Although circuit hyperexcitability a hallmark (FXS), cell-autonomous effects deficiency remain poorly understood. In this work, we investigated functional consequences absence on neuronal morphology ionotropic glutamate receptor surface distribution, using primary cultures mice hippocampal neurons isolated from wild-type (WT) knock-out (KO) pups. MAP2 staining KO showed decrease in total dendritic length complexity tree, accompanied increase soma size compared to WT neurons. Moreover, immunolabelling receptors performed under non-permeabilising conditions presented higher content GluN2A lower GluN2B subunits NMDA receptors, while GluA1 GluA2 distribution remained unchanged. Finally, multielectrode array data reduced spontaneous activity control These support hypothesis at cellular level, less excitable due altered input processing, driven structural defects expression plasma membrane.

Язык: Английский

Процитировано

0
Sculpting excitable membranes: voltage-gated ion channel delivery and distribution DOI
Sidharth Tyagi, Grant P. Higerd‐Rusli, Elizabeth J. Akin

и другие.

Nature reviews. Neuroscience, Год журнала: 2025, Номер unknown

Опубликована: Апрель 2, 2025

Язык: Английский

Процитировано

0
Live imaging of excitable axonal microdomains in ankyrin-G-GFP mice DOI Creative Commons
Christian Thome, Jan Maximilian Janssen, Seda Karabulut

и другие.

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2023, Номер unknown

Опубликована: Фев. 1, 2023

Abstract The axon initial segment (AIS) constitutes not only the site of action potential initiation, but also a hub for activity-dependent modulation output generation. Recent studies shedding light on AIS function used predominantly post-hoc approaches since no robust murine in vivo live reporters exist. Here, we introduce reporter line which is intrinsically labeled by an ankyrin-G-GFP fusion protein activated Cre recombinase, tagging native Ank3 gene. Using confocal, superresolution, and two-photon microscopy as well whole-cell patch-clamp recordings vitro, ex , confirm that subcellular scaffold electrophysiological parameters cells remain unchanged. We further uncover rapid remodeling following increased network activity this model system, highly reproducible labeling over weeks. This novel allows longitudinal plasticity real-time thus provides unique approach to study broad range applications.

Язык: Английский

Процитировано

8
Actin polymerization and longitudinal actin fibers in axon initial segment plasticity DOI Creative Commons
David Micinski, Pirta Hotulainen

Frontiers in Molecular Neuroscience, Год журнала: 2024, Номер 17

Опубликована: Май 10, 2024

The location of the axon initial segment (AIS) at junction between soma and neurons makes it instrumental in maintaining neural polarity as site for action potential generation. AIS is also capable large-scale relocation an activity-dependent manner. This represents a form homeostatic plasticity which regulate their own excitability by changing size and/or position AIS. While important proper functionality AIS-containing neurons, cellular molecular mechanisms are poorly understood. Here, we analyzed changes actin cytoskeleton during using 3D structured illumination microscopy (3D-SIM). We showed that number longitudinal fibers increased transiently 3 h after induction. further polymerization, especially formin mediated required formation fibers. From family proteins, Daam1 localized to ends These results indicate active re-organization plasticity.

Язык: Английский

Процитировано

2
Unveiling the cell biology of hippocampal neurons with dendritic axon origin DOI
Yuhao Han, Daniela Hacker, Bronte C Donders

и другие.

The Journal of Cell Biology, Год журнала: 2024, Номер 224(1)

Опубликована: Сен. 24, 2024

In mammalian axon-carrying–dendrite (AcD) neurons, the axon emanates from a basal dendrite, instead of soma, to create privileged route for action potential generation at initial segment (AIS). However, it is unclear how such unusual morphology established and whether structure function AIS in AcD neurons are preserved. By using dissociated hippocampal cultures as model, we show that development can occur prior synaptogenesis independently vivo environment. A single precursor neurite first gives rise then AcD. The possesses similar cytoskeletal architecture soma-derived similarly functions trafficking barrier retain axon-specific molecular composition. does not undergo homeostatic plasticity, contains lesser cisternal organelles, receives fewer inhibitory inputs. Our findings reveal insights into neuron biology underscore structural differences based on onset.

Язык: Английский

Процитировано

2